A conventional image processing apparatus has a fixing apparatus for fixing a toner image transferred onto a sheet. In the fixing apparatus, sheet is conveyed in a sheet conveyance direction by a rotating body such as a belt or a roller. The fixing apparatus has a heating section such as a halogen lamp for heating the sheet. The fixing apparatus has two heating sections in some cases. For example, one of the heating sections is a center lamp mainly heating a central part of the sheet in a direction orthogonal to the sheet conveyance direction. The other one of the heating sections is a side lamp mainly heating both ends in the direction orthogonal to the sheet conveyance direction.
For example, the fixing apparatus has three temperature sensors that detect a temperature of the rotating body. One of the three temperature sensors is a center temperature sensor which detects the temperature of a part of the rotating body that the center lamp mainly heats. The other one of the three temperature sensors is a side temperature sensor that detects the temperature of a part of the rotating body that the side lamp mainly heats. The remaining one of the three temperature sensors is a side temperature sensor that detects a temperature of a non-heating area of the rotating body which is not heated by any heating section.